Dear Ghop,
Excellent and important questions!
Let's look at each one.
"How do we return the mind to the mantra without effort? Does not any thought, however subtle, require some effort of the will, or concentration, to return to when we have forgotten it?"
Yes, this is indeed the situation in our daily life, in the waking state of physiology. This is why commonsense is not always a reliable guide. Commonsense is based on what we know and have experienced. For example, commonsense tells us that nothing can be in two places at the same time, that liquids cannot flow uphill, and that any wire has some degree of electrical resistance. Yet each one of these 'obvious facts' has exceptions when quantum mechanical effects dominate. For example, very cold liquid helium easily flows uphill (due to superfluidity).
The failure of commonsense to account for quantum mechanical phenomena is just an analogy, of course. The fact is, the reason for effort in thinking (such as when problem solving) is stress (see
http://www.nsrusa.org/about-stress.php). Stress interferes with clear thinking and makes it necessary to exert effort to complete a logical sequence of thoughts. Compare this need for effort with the effortlessness of solving a problem through spontaneous intuition, or during a dream. The answer just flashes into our mind. How can that happen? It happens because we are not consciously in control of most of our mental abilities. For example, what happens before we give a friend advice about what to do in an important personal situation? We must consider many aspects of the situation and many pros and cons about each possible approach to resolving it. Yet what we are conscious of is simply speaking from the heart, somehow knowing that what we are saying is reliable to the best of our ability.
When we practice NSR Meditation for some months or years, we eliminate enough stress so that the need for effort disappears. Just as when we are giving a friend good advice, all goals become easier to plan and achieve. In fact, the process becomes so automatic and efficient that the answers simply spring to mind. Problem solving no longer has to be laborious, since there are fewer stresses to fight against.
When we practice transcending, we are reversing the usual concrete thinking mode, diving within to less active, less concrete modes of thinking. Feeling is an example of a less concrete mode: it takes no effort to feel an emotion, it just happens. In the same way, we start with the syllable as a concrete sound, but then let go. Since the syllable is "slippery", easy to forget, it leads the mind in the direction of transcendence: awareness without thinking. Awareness, like emotion, takes no effort. So why should thinking the syllable take effort? The only way is if we think the syllable on the surface, concrete level. But this is not what we are doing; we are thinking the syllable only as a faint thought, as a feeling. Feelings are effortless, remember? So transcending using the syllable is naturally effortless.
"It also says to think the mantra in the way that it comes naturally in the mind. What if it doesn't come at all? Do I start repeating it in the beginning and then just let it come or go as the process unfolds?"
We start the mantra after the period of silence and then let go. If the mantra doesn't come at all, that's fine. It just means that there's lots of stress near the surface, ready to release. If we were to come back to the mantra clearly, we would disallow transcending, which would take effort. Any effort during meditation, such as forcing the mantra to be clear and distinct (concrete), opposes the whole goal of meditation. It generates mental discomfort, prevents expansion of the mind, and interferes with dissolving stress.
Maybe the problem is that you think you are supposed to repeat the mantra. No, you are supposed to come back to a feeling of the mantra. It is quite different. This is the key that makes TM and NSR so impressively effective at improving life as compared with other self-improvement techniques, and why this knowledge disappeared thousands of years ago. It is just not obvious; it seems wrong by commonsense. Yet anyone who learns how to transcend knows that it is natural, simple, innocent, and spontaneous.
"When 'thinking' the mantra, is this done on an auditory level? In other words, do I imagine that I am mentally 'hearing' the mantra in my consciousness, or just thinking the thought of it?"
My feeling is that if we analyze too much we'll lose the innocence that makes the process work. We don't imagine anything. We just start the mantra and take it as it comes. Since there is an enormous range of ways that we can experience this, it is counterproductive to be more specific. The mantra can be forgotten as we get lost in a train of thoughts (side effects of dissolving stress). The mantra can be very distinct and clear, yet effortless. The mantra can be present along with other thoughts, like two friends walking along a beach. Anything that happens is good. The variety of experiences results from the dynamic nature of stored stress. Different people will experience transcending in different ways, and these experiences will change over time. Analysis is not helpful; acceptance is.
If you still have questions after reading this, read the many other postings here on the subject of effortlessness. Other clients have reported that a particular answer spoke to them in a unique way that they found helpful.
David Spector
NSR Meditation/USA